Researchers from Caltech have developed a fluid-like chain mail that can stiffen itself on command. The material could offer exoskeletons unmatched flexibility, while also being capable of protecting in its stiff state.
The team that works at NASA’s JPL managed by Caltech hints that the same material can be useful for providing structure while an injury heals. “We wanted to make materials that can change stiffness on command,” said Chiara Daraio, corresponding author of the study. “We’d like to create a fabric that goes from soft and foldable to rigid and load-bearing in a controllable way.”
Made of complex polymers and metals
“Think about coffee in a vacuum-sealed bag,” Daraio added. “When still packed, it is solid, via a process we call ‘jamming.’ But as soon as you open the package, the coffee grounds are no longer jammed against each other and you can pour them as though they were a fluid.”
But instead of being made up of coffee grounds, the chain mail is made of complex interlocking shapes, 3D-printed with help of polymers and metals.
“In this chain mail application, the ability to carry tensile loads at the grain scale is a game changer,” said Jose Andrade, Caltech mechanical engineering professor. “It’s like having a string that can carry compressive loads.”
Sturdy and durable material
During the lab tests, the team learned that its material can withstand more than 50 times its own weight when stiffened. Now, researchers are seeking ways to switch the material from its rigid to its fluid state and vice versa.
Previously, Engineers at Washington University in St. Louis have managed to develop a new amyloid silk hybrid protein and produced it in engineered bacteria. The team found out that the fiber made from the material are stronger than natural spider silks.
Besides, researchers at UC San Diego have developed a new wearable device that can charge small devices and sensors. The thin and flexible strip can be placed on a fingertip and it will produce small amounts of power when the user’s finger sweats or presses on it.
